Esotropia

Diagnosis Instill 1 drop of 0.125% solution once a day into both eyes at bedtime for 2 or 3 weeks. If the esotropia is accommodative, a favorable response may begin within a few hours. 

The major therapeutic uses of the cholinomimetics are for diseases of the eye (glaucoma, accommodative esotropia), the gastrointestinal and urinary tracts (postoperative atony, neurogenic bladder), the neuromuscular junction (myasthenia gravis, curare-induced neuromuscular paralysis), and very rarely, the heart (certain atrial arrhythmias). Cholinesterase inhibitors are occasionally used in the treatment of atropine overdosage. Several newer cholinesterase inhibitors are being used to treat patients with Alzheimer s disease. 

Accommodative esotropia (strabismus caused by hypermetropic accommodative error) in young children is sometimes diagnosed and treated with cholinomimetic agonists. Dosage is similar to or higher than that used for glaucoma. 

Primary or secondary esotropia or exotropia Nonconcomitant misalignment... 

Esotropia (an inward squint) has been reported in a patient taking olanzapine and fluoxetine for psychosis it resolved promptly on withdrawal of olanzapine (133). 

Singh HK, Markowitz GD, Myers G. Esotropia associated with olanzapine. J Clin Psychopharmacol 2000 20(4) 488. 

Seven cases of acute strabismus related to opiate abuse in Switzerland between 1993 and 2001 have been reported (35). In five cases the symptoms coincided with heroin withdrawal and acute esotropia occurred a few days after heroin was stopped. The other two patients developed acute exotropia that was related to opiate abuse. All the symptoms disappeared spontaneously. It is likely that changes in the blood opioid concentration disrupted the oculomotor system and affected binocular vision, although the exact mechanism underlying this phenomenon is not known. 

The therapeutic indications for BoNTs are numerous. They are used in the treatment of ophthahnological disorders (strabismus, Duane s syndrome, esotropia/exotropia), movement disorders (focal dystonias, blepharospasm), spasticity, neiuomuscular disorders, pain (headache, myo-facial pain), disorders of the pelvic floor (anal fissures), ear/ nose/throat disorders, cosmetic applications (wrinkles), and hyperhidrosis. The recent explosion in new indications for BoNTs in the treatment of a wide range of medical conditions also brings the possibihty for medical errors in BoNT dosing. Systemic botulism may result from injection of excessive doses of the potent neurotoxin. The most infamous case of systemic botulism involved the paralysis of four Florida patients, including the doctor, treated with BoNTs for wrinkles. The physician used non-FDA approved formulations of type A from Toxin Research International,... 

Cycloplegia is reserved for a limited number of conditions (e g., suspected latent hyperopia, accommodative esotropia, amblyopia treatment). Hyperopic patients may have shallow anterior chamber angles that require... 

The drug can also be used concomitantly with echo-thiophate to prevent the formation of miotic cysts during treatment of open-angle glaucoma or accommodative esotropia. Addition of the 2.5% concentration to the echothiophate regimen is recommended. The mechanism whereby phenylephrine prevents cyst formation is not known. However, inhibition of the intense miosis may account, at least in part, for the beneficial effect. 

Tropicamide, like atropine, cyclopentolate, and scopolamine, enters the systemic circulation rapidly. After applying two 40-ml drops of 0.5% tropicamide to one eye in eight patients, peak plasma concentrations were reached in 5 to 30 minutes but were variable (1.3 to 5.2 ng/ml).A mean peak concentration of 2.8 ng/ml was measured at 5 minutes. Despite the rapid systemic absorption, tropicamide has a low affinity for systemic muscarinic receptors.Thus adverse systemic reactions to tropicamide are quite rare. Two studies observed no significant adverse reactions associated with the use of tropicamide in 3,851 drug applications in patients undergoing ophthalmoscopy with either 0.5% or 1% tropicamide.The only reported effects were mild and transient transient changes in lOP on the order of 4 to 12 mm occurred in seven patients, and one individual experienced a transient intermittent esotropia. 

The mean refractive difference in esotropic children between 3 months and 6 years of age was 0.34D more hyperopia when 1% atropine was used versus 1% cyclopentolate. This study implies that, clinically, cyclopentolate is sufficient for cycloplegic retinoscopy. However, in a subgroup of 22% of children, atropine uncovered an additional -i-l. OOD or more of hyperopia. Almost all children in this subgroup demonstrated -1-2.OOD or more on their initial cyclopentolate retinoscopy. Therefore the use of atropine may prove more important in children who have moderate hyperopia and esotropia. 

Are there any binocular or accommodative disorders that the refractive correction would improve For example, in the case of refractive/accommodative esotropia, the prescription for hyperopic correction is critical in reducing or eliminating the esotropia. 

Would refractive correction prevent future problems from developing For example, if a preschool-aged child is found to have moderate hyperopia, by prescribing spectacles the clinician may prevent the child from developing refractive/accommodative esotropia. 

Celebi S, Aykan U. The comparison of cyclopentolate and atropine in patients with refractive accommodative esotropia by means of retinoscopy autorefractometry and biometric lens thickness.Acta Ophthalmol Scand 1999 77 426-429. Drug facts and comparisons. St. Louis, MO Wolters Kluwer Health, 2006. 

An additional concern in the use of miotics in lieu of spectacles arises in the case of anisometropia associated with significant hyperopia and accommodative esotropia. 

Infantile and acquired esotropia of mild to moderate size... 

Not without controversy, it appears that botulinum injection offers a safe and reliable alternative to surgical intervention of infentile esotropia. Although additional long-term follow-up studies are needed, the ability to promote binocularity during the period of visual development is desirable and can be accomplished with the use of this agent. 

In summary, the mounting evidence supports the use of botulinum toxin in treating various forms of strabismus. These conditions include chronic and acute sixth nerve palsy, infantile esotropia, luidercorrection or overcorrection of strabismus with some residual level of binocularity,... 

Biglan AW, Burnstine RA, Rogers GL, et al. Management of strabismus with botuUnum toxin injection in infantile esotropia. Ophthalmology 1989 96 935-943. 

Campos EC, Schiavi C, BeUusci C. Critical age of bomlinum toxin treatment in essential hifantile esotropia. J Pediatr Ophthalmol Strabismus 2000 37 328-332. 

McNeer K Tucker MG, Guerry CH, et al. Incidence of stereopsis after treatment of infantile esotropia with bomlinum toxin A. J Pediatr Ophthalmol Strabismus 2003 40 288-292. 

McNeer KW, Tucker MG, Spencer RE Management of essential infantile esotropia with botulinum toxin A review and recommendations. J Pediatr Ophthalmol Strabismus 2000 37 63-67. 

Repka MX,Wellish K,Wisnicki FIJ, et al. Changes in the refractive error of 94 spectacle treated patients with acquired accommodative esotropia. Binocular Vision 1989 4 15-21. 

---